Valve deactivator lifter assemblies are used in connection with an overhead cam valve train of an internal combustion engine or for engines with overhead-valve pushrod type valve trains. One type of valve deactivator for overhead cam engines is a stationary hydraulic lash adjuster (“SHLA”) such as those described in commonly owned U.S. Pat. No. 6,681,734 and U.S. Pat. No. 6,584,942. Typically, a pre-selected number of the engine cylinders are equipped with a deactivator connected to an associated intake engine poppet valve. In a latched condition, the deactivator is locked allowing for normal operation of the valve train. Movement of the latch assembly from the latched position to the unlatched position is achieved by increasing engine oil hydraulic pressure in a specific designated fluid circuit. In this position, engine poppet valve is deactivated.
For a valve train, prior art deactivator lifting assemblies include latching elements typically in the form of using circular pins between inner and the outer bodies of the deactivator where the pins co-act with a receiving groove where the circular pin has a somewhat flattened base. A deactivator lifter assembly, upon driver selection or predetermined road conditions, introduces sufficient lost motion into the valve train so to retain a cylinder poppet valve in the closed position. Accordingly, a deactivator lifter assembly, includes a latch assembly, switchable between a latched (poppet valve active) and unlatched (poppet valve deactivated) condition.
Notwithstanding the usefulness of the above-constructs a need still exists for enhancing reliable operability and structural integrity of valve deactivators.